The Home Office's latest attempts to justify its calculations of the cost and benefits of the national ID card scheme have been branded misleading and inaccurate by the London School of Economics (LSE).

The Home Office last month published its first detailed public response to LSE claims that the ID card scheme could cost £19bn — more than three times Home Office estimates.

The LSE was accused of using "inaccurate assumptions" — such as the claim that cards would need to be replaced more than once every 10 years — to inflate estimates.

But the LSE has hit back with details that cast further doubt over the technical specification of ID cards and the government's cost/benefit analysis of the scheme, and said crumbling public and political support will have an adverse effect on the likelihood of its success.

The LSE report said: "Securing and maintaining a public consensus that is overwhelmingly supportive of a new ID card scheme will be fundamental to its likely costs, implementation timetable and future efficacy. We believe it is plain to all impartial observers that the current Home Office scheme does not command such support."

The LSE claims the Home Office response contains "substantial material errors and misrepresentation of fact" relating to population data and card loss, damage and replacement rates.

Home Office minister Tony McNulty admitted this week that the government had "oversold" the case for ID cards, and Simon Davies, visiting fellow at the LSE, said support for the scheme is vanishing fast.

"There is a critical mass of opposition where it suddenly becomes unfashionable to support something and I think that point has been reached with ID cards," he said.